Hungry eagle foils heron recovery near Basalt | VailDaily.com

Hungry eagle foils heron recovery near Basalt

Scott Condon
Basalt, CO Colorado

BASALT, Colorado – Just when it looked like a great blue heron colony was going to be re-established near Basal this spring, a golden eagle turned a nursery into a buffet.

The eagle devoured heron chicks and eggs from six nests on Rock Bottom Ranch, near Basalt, between May 28 and June 6, saidto Mary Harris, a resident of the area and avid bird watcher.

“He just gobbled up everything,” she said.

While it is easy to write off the attack as an act of nature, the timing couldn’t be worse. The nesting areas at Rock Bottom Ranch, after consistent use as a rookery in the spring, have been abandoned in recent years.

Wildlife enthusiasts contend that the opening of the nearby Rio Grande Trail has contributed to the flight of the herons. They have asked the Roaring Fork Transportation Authority to delay the opening of the trail until later in the spring. Currently, a 2 1⁄2-mile section of the trail is closed from Dec. 1 until May 1.

Harris said cold and wet weather this May limited use of the trail, so the herons weren’t spooked from the site. That was important, she said, because once the chicks hatch, the adults will stay put.

Her neighbor, Jim Biebl, kept a log of heron activity this spring. On April 22, he observed five herons sitting on nests and 14 altogether hanging out in the Rock Bottom Ranch area. Males would catch fish and bring them back to the females on the nests, he said.

Unlike the prior two years, the herons didn’t scram when the trail opened on May 1, and the number of nests with sitting herons grew to six.

Biebl said the first observed herons hatched on May 15. But the success story turned somewhat sour on May 28 when the Harrises and the Biebls noticed the adult herons were extremely agitated. The problem was obvious when the families observed the nesting grounds.

“It was a golden eagle chowing down on little herons and eggs,” Biebl said.

Although agitated, the adult herons did little to defend their territory or offspring. Ravens and osprey nesting in the area dive-bombed the eagle to try to drive it away, without success.

One of the rare defensive maneuvers by an adult heron was captured in a photo. Mary Harris and Jim’s daughter, Brittany, teamed on June 3 to take a picture of a heron trying to defend a nest. Mary said she put a digital camera to her telescopic lens while Brittany used another telescope to tell her when to take a photo. They hope to enter one of the best photos in an National Audubon Society contest.

Harris said the eagle kept returning to the colony and feasting on the eggs and chicks. It was like candy laid out for a kid, she said.

The eagle scored its biggest haul Saturday when it invaded a nest with four rapidly growing heron chicks. It killed and devoured all four, although some probably fell out of the nest while trying to escape, Biebl said.

With all the chicks dead and the eggs destroyed, the adults fled the area.

“Besides being really sad, it was really wild watching it,” said Biebl.

Harris said the incident shows humans should assist development of heron rookeries. The birds aren’t endangered, and there are at least three other colonies in the Roaring Fork Valley. However, the Rock Bottom feeding frenzy shows that more rookeries are better for the herons.


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